NATURAL PHILOSOPHY. 153 



interfere and blend with the signal preceding. The difficulty was quite 

 unexpected. Faraday brought his wonderful power of investigation to bear on 

 the subject, and ascertained that the conducting property of sea water on the 

 outside of the gutta-percha has the effect of converting the coated wire into an 

 elongated Leyden jar. and causes it to retain a portion of the charge, hi the same 

 manner as an ordinary Leyden jar retains a part of the electricity after it has 

 been discharged. This difficulty, which seemed to present an effectual bar to 

 the use of Professor Morse's instruments in which the electric current tra- 

 verses continuously in the same direction was overcome by reversing the 

 direction of the current after each signal, by which process the wire was pre- 

 pared to transmit another. That plan has answered from London to the 

 Hague, but doubt is entertained whether the remedy will apply across the 

 Atlantic. Experiments, so far as they can be made, show that the obstacle 

 may be overcome ; but theoretical philosophers are not wanting, who, armed 

 with arrays of figures, contend that the thing is impossible." 



During the past summer, the U. S. steamer Arctic, was sent out to run aline 

 of soundings from Newfoundland to the nearest point on the Irish coast, with 

 a view of affording information relative to the laying of the proposed tele- 

 graph. The result of the expedition has been stated by one of the party as 

 follows : 



"Not a single rock had been met with, not a particle of gravel or sand had 

 been brought up, but it appears as if nature had provided a bed ' soft as a 

 snow bank,' to use Maury's own words, for the express purpose of receiving a 

 telegraph cable. 



"Lieut. Berryman says that he is satisfied that the lead, with the sounding 

 apparatus, has frequently buried itself ten or fifteen feet deep in this soft 

 material, and he doubts not that the cable will likewise sink and imbed itself 

 in a similar manner. The greatest depth attained has been two thousand and 

 seventy fathoms (about two and a third miles) ; but perhaps the most remarkable, 

 and at the same tune the most satisfactory result, is the perfect confirmation 

 which these soundings give of the opinion expressed by Lieut. Maury as to the 

 existence of a great flat or level at the bottom of the ocean, unparalleled by 

 anything on the surface of the earth, and which he proposes to name the 

 ' Telegraph Plateau.' For more than thirteen hundred miles the body of the 

 Atlantic, in the direct line of our track, is found by these soundings to present 

 an almost unbroken level plain. Nature has thus placed no obstacle in the 

 way of this great undertaking, which may not, by cautious perseverance, be 

 overcome ; nay, rather (if we except the enormous length of the cable which 

 will be required) it would seem that the line to be followed by the Atlantic 

 cable presents absolutely fewer engineering difficulties than the shorter 

 route (though more complex, from the nature of the bottom) on which the 

 Mediterranean cable must be laid." 



During the last few weeks of the year, the enterprise of constructing the 

 Transatlantic telegraph has been pushed forward with vigor. The whole 

 amount necessary for the construction of the work has been subscribed in 

 England and the United States, and contracts for the manufacture of the cable 

 have been made. By the terms of the contracts, the cable is to be completed 



